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Steel HPM38 QT50-52 vs HPM38 QT52-54

Steel · HPM38 temper comparison

HPM38 QT50-52 and HPM38 QT52-54 are two conditions of the same steel grade, HPM38: QT50-52 (hardened & tempered 50–52 HRC) versus QT52-54 (hardened & tempered 52–54 HRC). The chemistry is identical, so every difference below comes from the condition. HPM38 QT52-54 is the stronger of the two: yield strength 1,620 MPa (235 ksi) against 1,520 MPa (220 ksi) for HPM38 QT50-52, about 7% more; tensile strength follows at 1,900 MPa (276 ksi) vs 1,780 MPa (258 ksi). In exchange, HPM38 QT50-52 is the more ductile: elongation 5% versus 3% for HPM38 QT52-54, and HPM38 QT52-54 is harder (580 HV vs 545 HV). On the shop floor, HPM38 QT52-54 welds better (25 vs 15 out of 100).

HPM38 QT50-52Choose it when the part is bent, formed or impact-loaded.

HPM38 QT52-54Choose it when strength drives the design, or when it will be welded.

HPM38 QT50-52 vs HPM38 QT52-54: properties

HPM38 QT50-52HPM38 QT52-54

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,780 MPa258 ksi
1,900 MPa276 ksi

Yield Strength (0.2% offset)

1,520 MPa220 ksi
1,620 MPa235 ksi

Elongation at Break

5%
3%

Compressive Strength

1,900 MPa276 ksi
2,050 MPa297 ksi

Shear Strength

1,050 MPa152 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

730 MPa106 ksi
760 MPa110 ksi

Fracture Toughness (K_IC)

24 MPa·√m21.8 ksi·√in
20 MPa·√m18.2 ksi·√in

Charpy V-Notch Impact (RT)

11 J8.1 ft·lbf
8 J5.9 ft·lbf

Hardness, Rockwell C

51 HRC
53 HRC

Hardness, Vickers

545 HV
580 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 45% · Hardness, Brinell 215 HB

Physical

Density and transition temperatures.

Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

How each material carries heat and how hot it can run.

Same in both: Thermal Conductivity 20 W/m·K11.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.8 µm/m·K6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 180°C356 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

57 / 100
58 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.35 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

15 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

12%
8%

Weldability

15 / 100
25 / 100

Polishability

97 / 100
96 / 100

Same in both: Formability (cold) 25 / 100 · Castability 20 / 100 · Brazeability / Solderability 30 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 52 MJ/kg22,356 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 90 L/kg10.8 gal/lb · Typical Recycled Content 40%

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleHPM38

HPM38 QT50-52 vs HPM38 QT52-54 — frequently asked

Is HPM38 QT52-54 stronger than HPM38 QT50-52?

Yes. HPM38 QT52-54 has a typical yield strength of 1,620 MPa (235 ksi) against 1,520 MPa (220 ksi) for HPM38 QT50-52 — about 7% more. Tensile strength is 1,900 MPa (276 ksi) vs 1,780 MPa (258 ksi).

Which condition does FabDigit quote by default, QT50-52 or QT52-54?

ANN is the default HPM38 condition in the FabDigit quote flow (neither QT50-52 nor QT52-54). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, HPM38 QT50-52 or HPM38 QT52-54?

HPM38 QT50-52. Its machinability rates poor (15/100) against not recommended (10/100) for HPM38 QT52-54; for welding the order is HPM38 QT52-54 first (poor, 25/100) then HPM38 QT50-52 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in HPM38 QT50-52 and HPM38 QT52-54 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.